Ears Facts & Worksheets

Hearing and body balance utilizing the vestibular system are both ear functions in mammals. Mammal ear parts are frequently referred to as the inner ear, middle ear, and outer ear, and the pinna and ear canal make up the outer ear.

See the fact file below for more information on the Ears, or you can download our 29-page Ears worksheet pack to utilize within the classroom or home environment.

Key Facts & Information

STRUCTURE

• The outer ear, middle ear, and inner ear are the three components of the human ear. The eardrum separates the air-filled tympanic cavity of the middle ear from the ear canal of the outer ear. 
• The pharyngeal aperture of the Eustachian tube connects the middle ear, which houses the three tiny bones known as ossicles that are important in sound transmission, to the throat at the nasopharynx. 
• The cochlea of the auditory system, the vestibular system’s semicircular canals, and the otolith organs—the utricle and saccule—all reside in the inner ear.

OUTER EAR

• The auricle (sometimes referred to as the ear canal, pinna, and the outer ear) is also referred to as the auris, or external ear.

AURICLE

• Particularly in other animals, the visible portion is referred to as the auricle, also known as the pinna.
• It is made up of a thin plate of yellow, elastic cartilage that is coated with integument, attached to the surrounding structures by ligaments and muscles, and connected to the beginning of the ear canal by fibrous tissue.
• Like how they can bend their eyes, many mammals can move the pinna (with the auriculares muscles) to focus their hearing in a specific direction. The majority of people lack this skill.
• Its primary function is to collect sounds and direct them toward the ear canal, which serves as the entrance to the middle ear. 
• Earwax protects the ear canal by sweeping away debris and warding off infections. Glands produce it in the skin that lines the ear canal.

EAR CANAL

• The canal joining the middle ear to the outer ear is called the external acoustic meatus, also referred to as the external auditory meatus or EAM. The mature human ear canal measures around 0.7 centimeters (0.3 in) in diameter and 2.5 centimeters (1 in) in length from the pinna to the eardrum.
• There are two sections to the human ear canal. The outer third of the channel is made up of elastic cartilage; its front and lower walls are cartilaginous, while its back and superior walls are fibrous. 
• The pinna’s cartilage framework continues in the cartilage. The cartilaginous section of the ear canal has little hairs and apocrine glands, which are specialized sweat glands that produce cerumen (ear wax).
• The inner two-thirds are made up of the bony component. In youngsters, the bony portion is substantially shorter; in newborns, it is merely a ring (annulus tympanic). In comparison to the cartilaginous section of the ear canal, the layer of epithelium covering the bony portion is much thinner and more sensitive.
• Everybody has a different canal size and form. The canal has a diameter of 0.7 centimeters (0.28 in) and measures about 2.5 centimeters (1 in) in length. It has a sigmoid shape and advances downward and from above. Its cross-section shows that it has an oval shape. When earplugs are fitted, these are crucial variables to take into account.

MUSCLES

FUNCTION OF THE OUTER EAR

• One effect of the outer ear’s design is a 30- to 100-fold increase in sound pressure at frequencies around 3 kHz. Humans are more sensitive to frequencies in this range due to this amplification, which also explains why they are more vulnerable to hearing loss and auditory damage close to this frequency. Most human-speaking sounds are spread out over a bandwidth of about 3 kHz.

MIDDLE EAR

• The middle ear is the area of the ear between the eardrum and the oval window of the cochlea (of the inner ear).

OSSICLES

• The malleus, incus, and stapes are three little bones that make up the middle ear. Ossicles are referred to as the anvil, hammer, and stirrup. Their Latin names were given to them because of their unusual shapes. 
• The cochlea’s oval window receives sound energy directly from the eardrum through the ossicles. The malleus and incus originated from the lower and upper jaw bones seen in reptiles, whereas the stapes are present in all tetrapods.
• According to traditional theory, the ossicles, with a lever arm factor of 1.3, mechanically convert eardrum vibrations into amplified pressure waves in the cochlea’s fluid (or inner ear). 
• As a result of the sound pressure being focused due to the eardrum’s effective vibratory area being approximately 14 times larger than the oval window, there is at least an 18.1 pressure gain.

MUSCLES

• Two muscles may stiffen the ossicles’ ability to move. The medial pterygoid nerve, which is a branch of the mandibular nerve of the trigeminal nerve, controls the tensor tympani muscle, which is linked to the top of the medial surface of the malleus handle and is regulated by the facial nerve. 

FUNCTION

• The majority of the energy is often reflected off the liquid’s surface when sound waves traveling through the air collide with it. 
• The middle ear enables the impedance matching of acoustic waves flowing through the inner ears’ fluid and membrane system to sound waves traveling in the air. 
• This system should not confuse the compression waves that travel through liquids.
• The middle ear uses the “hydraulic principle” and the “lever principle” as well as “mechanical advantage” to couple sound from the air to the fluid via the oval window.

INNER EAR

• The deepest portion of the vertebrate ear is known as the inner ear (internal ear, auris interna). The inner ear is primarily responsible for sound perception and balance in vertebrates. 
• It is made up of the bony labyrinth in mammals, which is a hollow space that can be found in the temporal bone of the skull with a network of channels divided into two main functional sections:
  • The cochlea, responsible for hearing, transforms sound pressure patterns from the outer ear into electrochemical impulses that are then sent from the auditory nerve to the brain
  • The balance-related vestibular system
• All vertebrates have an inner ear, but their form and function differ significantly. In all vertebrates, the eighth cranial nerve innervates the inner ear.

BONY AND MEMBRANOUS LABYRINTHS

• The network of channels with bony walls lined with periosteum is known as the “osseous labyrinth” or “bony labyrinth.” The three main components of the bone labyrinth are the semicircular canals, the vestibule of the ear, and the cochlea. 
• The membranous labyrinth, which creates three parallel fluid-filled chambers, runs inside the bony labyrinth. The inner and two outer halves are both filled with endolymph.

VESTIBULAR AND COCHLEAR SYSTEMS

• The known three auditory ossicles in the middle ear convert pressure wave energy into mechanical vibrations. 
• The tympanic membrane is moved by pressure waves, which in turn move the malleus, the first bone of the middle ear. The incus and malleus articulate to form the stapes.
• The circle beginning with the window is joined to the stapes footplate via the inner ear.

CLINICAL SIGNIFICANCE

HEARING LOSS

• Partial or complete hearing loss is possible. This could result from damage, injury, hereditary illness, or physiological reasons. Conductive hearing loss refers to hearing loss brought on by harm to the middle or outer ear.
• When damage to the brain, vestibulocochlear nerve, or inner ear is the underlying cause of deafness, the condition is called sensorineural hearing loss.
• Ossicles that are absent, fused, or blocked, as well as perforations in the eardrum, can cause conductive hearing loss. 
• Conductive hearing loss may also arise from middle ear inflammation producing fluid build-up in the air-filled region, such as by otitis media.
• If the hearing loss is severe or ongoing, cochlear implants or hearing aids may be used. Hearing aids boost the sound of the immediate environment and are best suited to conductive hearing loss. 

EARS AND SOCIETY

• Since ancient times, people have adorned their ears with jewelry by traditionally piercing their earlobes. Ancient and contemporary cultures have used ornaments to stretch and extend the earlobes, making it possible to slide larger plugs into a wide, fleshy opening in the lobe. It is extremely common for the earlobe to tear due to the weight of thick earrings or from the traumatizing pull of an earring (for instance, from snagging on clothing).
• The practice of injuring the ears as a form of reprimand or punishment dates back to Roman times. 
• The pinnae influence how the face looks. About 5% of ethnic Europeans have prominent ears, historically viewed as ugly, mainly if asymmetrical. Ernst Dieffenbach reported the first surgical procedure to lessen the projection of prominent ears in the medical literature in 1845, and the first case study followed in 1881.
• Folklore creatures like the Japanese earth spider, Brazilian Curupira, and French croquemitaine have pointy ears. It has been a characteristic of characters in ancient Greek and medieval European artwork. Elves, faeries, fairies, hobbits, and orcs are just a few fantasy species that frequently have pointed ears.

Ears Worksheets

This fantastic bundle includes everything you need to know about the Ears across 29 in-depth pages. These ready-to-use worksheets are perfect for teaching kids about the Ears, an incredibly intricate structure composed of three parts, the inner, middle and outer ear that work together to detect sound waves.

Download includes the following worksheets

• Ears Facts
• Inner, Middle, Outer 
• Superb Ear
• Ear Anatomy
• My Ears
• Use Your Ears
• What’s My Role?
• World Hearing Day
• Noise Pollution
• Hearing Disability
• Ears and My Life

Frequently Asked Questions

What is unique about the human ear?

The stapes, also known as the “stirrup” bone, located in the middle ear, are the tiniest of all bones in human anatomy. This tiny ossicle forms an essential part of our auditory system and allows us to hear various sounds.

How do ears work?

Sound waves enter your ear canal and are intensified. The sound waves then hit a thin, oval-shaped membrane at the end of the ear canal called the eardrum. This makes the eardrum vibrate.

Can we live without ears?

It would be more difficult to hear without the outer part of your ear. This is because the outer part of your ear collects sound and sends it into the inner canal. So this part of the ear helps us to hear better.

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